Much of the beach is open to vehicles. You can get a current map from the BLM to check if you were in one of those areas. Generally driving along the waterfront is tolerated over most of the beach, but there’s only limited dunes access, and driving in the dunes outside of the areas on the map will get the sheriff’s jeep called out. Also, vehicles are required to drive slowly and carefully around people playing on the beach, speeding back up once they’re past anyone.